1. Field of the Invention
This invention relates to absorbent pads and, more particularly, to such pads which are designed for protecting bedding against soiling by incontinent patients, principally for use on beds in hospitals, nursing homes and the like.
2. Description of the Related Art
Various approaches to solving the problem of protecting bedding from incontinent patients are known in the prior art. For example, rubber sheets have been used, usually placed over a mattress and underneath the lower cloth sheet on a bed. While they serve the primary purpose of protecting the mattress, they are extremely uncomfortable for the patient.
Hospital underpads have been developed as a preferable alternative to the rubber sheet. Since these underpads are more comfortable for the patient to lie on in direct contact with, they are placed on top of the lower sheet, thereby protecting it as well as the mattress. One type of hospital underpad which has long been on the market comprises a plurality of soft, fibrous tissue layers backed by a soft, waterproof polyethylene backing layer. The four edges of the backing layer are turned and/or sealed. The absorbent tissue layers are uniform and lump free, and provide maximum absorbency and dispersion of liquid. Runoff or leakage is prevented by virtue of the sealed edges. Instead of the fibrous tissue layers, some underpads are formed of packed tissue or fluffed wood pulp. These hospital underpads are provided in appropriate sizes to cover the vulnerable area underneath the patient and are available in individual packs for ease of stocking and handling.
The turned edges of the hospital underpads just described present an upper surface of polyethylene or polypropylene backing which frequently comes in contact with the patient's skin where it can create "hot spots" or cause skin breakdown, resulting in bedsores which sometimes lead to a type of cancer. Bedsores are a serious problem with longer term bedridden patients, particularly the elderly. Statistics on the subject indicate that some 30,000 patients die of complications from bedsores every year. The problems are exacerbated with underpads that do not have the liquid absorbent capacity needed for comfort or which are not changed often enough.
Some of these hospital underpads are equipped with adhesive strips of pressure-sensitive tape or plastic melt or the like on the exposed surface of the backing layer in order to hold the underpad in place underneath the patient without bunching up or displacement from the desired position of maximum effectiveness. In some examples of the prior art, the bottommost absorbent layer is adhesively laminated to the impervious backing sheet.
In an effort to improve the absorbent capability of hospital underpads, variations have been developed in which wood pulp is interspersed with the soft fibrous tissue layers. Sometimes, a super-absorbent powder is mixed with the wood pulp in homogeneous distribution within the pad. Unfortunately, if such pads are left with a patient too long, the filling with liquid develops a slimy combination of the wood pulp, super-absorbent powder and urine that is particularly likely to cause skin breakdown if left in contact with the patient's body. Thus such arrangements, even though more absorbent, still do not provide a completely satisfactory answer to the problem of developing an absorbent underpad for incontinent patients. It is desirable, therefore, to provide a novel construction for hospital underpads which increases the absorbent capacity of the product to a significant extent over that of presently known absorbent underpads.